1. Field of the Invention
The present invention relates to paving stones of concrete or artificial stone for courtyard surfaces, pedestrian zones, garden layouts, horticultural grounds or the like, which have equal level and which have upright side walls as well as in essence quadratic, rectangular or trapezoidal-shaped area or base surfaces determined by a fixed module in the side dimensions thereof and which can be composed or placed together into patterns during placement thereof. Such patterns can be circular or sectors forming a circle. However, also other patterns closed in themselves in an irregular distribution of the individual types of stones can be placed, set or positioned.
2. Description of the Prior Art
The regularity of such stones produced in an industrial method or procedure results however in a monotony of the pavement composed thereof, which is not compatible with requirements set or encountered therewith for garden plots and park layouts, pedestrian zones and courtyard surfaces of residential installations. On the other hand, such a pavement must have a sufficient or adequate strength, stability or resistance against horizontal moveability or displaceability in order to avoid destruction, disintegration or failure via a horizontal thrust exerted by vehicles that are turning or being braked thereon.
In order to attain this, there are offered paving stones angularly toothed or cornered among each other which are adequate moreover as to the latter technical requirements, but offering an unsatisfactory aspect or appearance particularly just because of the regularity of the teeth, notching or dovetailing thereof.
In order to take into account the requirements as to structural shape, formation, appearance and architecturally, there were developed paving stones with which the contours of the vertical or upright side walls represent circular arches or arcs in a circle flat in horizontal section and the corners are rounded-off between the side walls. Together with the likewise rounded-off corners of the surface driven upon respectively walked upon there is to be aroused with such rounded-off corners the impression of an old worn-away natural stone (arch) pavement subjected to wearing out by driving thereon to appear like hand-hewn masonry stones. Aside therefrom, that also herewith a monotonous impression of identical shapes or forms repeating themselves is awakened, inspired or aroused, there must be noted that this configuration, construction or formation decided upon because of the aesthetic effect thereof also is technically disadvantageous, since the circular arc surfaces of the side walls engage themselves only linearly respectively and the rounded-off corners do not have any possibility of engagement or interlock with the adjoining stones. At the location of meeting or coming together of such rounded-off corners there results a comparatively large hollow space respectively during placement, setting or positioning thereof and this hollow space reduces the stability or strength of the pavement. Such stones accordingly can shift not only against each other but rather also can twist or turn themselves easily, whereby the rounded-off corners roll-off along the adjoining stones.
To be sure, this disadvantage is extensively reduced via flattening of these circular-arc surfaces of the side walls, even if also the round corners are left remaining, whereby a still stronger monotony of the set or positioned pavement surface results.
The irregularity of such stones produced in industrial procedure however does result in a monotony in the pavement composed of such stones which monotony of the pavement is not compatible with pedestrian zones provided in garden layouts and park grounds as well as courtyard surfacing of residential areas for which requirements must be met. On the other hand, such a pavement must have an adequate strength and rigidity against horizontal shiftability in order to avoid destruction via vehicles that are turning and or applying brakes in such a manner to exert a horizontal shift or thrust. In an attempt to attain this strength and rigidity there can be noted that square toothed pavement stones are offered which may approach a solution to the foregoing problems but additionally have an unsatisfactory appearance particularly because of the regularity of the toothed means thereof.
There are also pavement stones known with which the contours of the upright or vertical sidewalls in a horizontal section represent flat circular arcs and the corners between these sidewalls are rounded-off in order to try to meet the requirements from a structural and architectural standpoint. Together with the edges likewise rounded-off as to the top surface of the pavement stones used as a walkway respectively having a tread surface upon vehicles also can move, there is to be awakened or brought about therewith an impression of an old worn-off natural stone pavement consisting of hand-hewn stones. Aside therefrom that also a monotonous impression is awakened herewith due to repetitious identical shapes or forms, there can be noted that such configuration undertaken for the aesthetic effect thereof must be considered to be technically disadvantageous since the circular-arc surfaces of the sidewalls respectively engage each other only linearly and the rounded-off corners have absolutely no engagement possibility with the adjoining or neighboring stones. At the location of the meeting of such rounded-off corners there results a comparatively large hollow space or opening during placement and positioning of the respectively of the stones relative to each other and this hollow space or opening reduces the strength and rigidity of the pavement. Such stones consequently can shift not only with respect to each other but also can be turned or twisted easily whereby the rounded-off corners roll-off along the neighboring or adjoining stones.
By flattening of these circular-arc surfaces of the sidewalls there can be brought about reduction of this advantage even if also the round corners remain therewith, whereby a still stronger monotony results in the positioned pavement stone.
An object of the present invention with the stones of the initially mentioned type is to bring about a gap-free fitting of the stones in a union, assemblage, association or formation and to attain a prevention of slipping-off as to each other, shifting or twisting and turning during a horizontal thrust, without these stones in the formation appearing unattractive and monotonous.